Kiyoshi Yoshimoto

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By Petersen’s theorem, a bridgeless cubic multigraph has a 2-factor. H. Fleischner generalised this result to bridgeless multigraphs of minimum degree at least three by showing that every such multigraph has a spanning even subgraph. Our main result is that every bridgeless simple graph with minimum degree at least 3 has a spanning even subgraph in which(More)
Given an integer λ ≥ 2, a graph G = (V,E) and a spanning subgraph H of G (the backbone of G), a λ-backbone coloring of (G,H) is a proper vertex coloring V → {1, 2, . . .} of G, in which the colors assigned to adjacent vertices in H differ by at least λ. We study the case where the backbone is either a collection of pairwise disjoint stars or a matching. We(More)
By Petersen’s theorem, a bridgeless cubic graph has a 2-factor. H. Fleischner extended this result to bridgeless graphs of minimum degree at least three by showing that every such graph has a spanning even subgraph. Our main result is that, under the stronger hypothesis of 3-edge-connectivity, we can find a spanning even subgraph in which every component(More)
In this chapter we present some notations and give a survey of the existing results about three topics of graph theory that are considered in this thesis, namely: spanning 2-connected subgraphs of grid graphs, Ramsey numbers for paths versus other graphs, and a general framework for coloring problems. 1.1 Notation and terminology Throughout this thesis, we(More)